JP2019113412A - Load measurement device - Google Patents

Abstract

To provide a technology capable of accurately measuring a load acting on a sheet surface deforming in response to the load.SOLUTION: The present description disclosures a load measurement device for measuring a load acting on a sheet surface deforming in response to the load. The load measurement device includes a sensor device, and an arithmetic device connected to the sensor device. The sensor device includes an inertial sensor disposed on the sheet surface and a force sensor disposed on the sheet surface. The arithmetic device acquires detection values from the inertial sensor and the force sensor, calculates an attitude angle of the force sensor on the basis of the detection value of the inertial sensor, and corrects the detection value of the force sensor using the calculated attitude angle.SELECTED DRAWING: Figure 1

Description

  The technology disclosed herein relates to a load measuring device that measures a load acting on a seat surface.

  Patent Document 1 discloses a load measuring device that measures a load acting on a seat surface. The load measuring device includes a sensor device and an arithmetic device connected to the sensor device. The sensor device includes a force sensor disposed on the seat surface. The arithmetic device acquires a detected value from the force sensor.

Unexamined-Japanese-Patent No. 2000-211418

  A seat on which a passenger sits in a vehicle such as a car uses a flexible material to improve sitting comfort, and the seat surface deforms according to an applied load. When the technology of Patent Document 1 is applied to a sheet surface that is deformed according to a load, the main axis direction of the force sensor changes with the deformation of the sheet surface, and the load acting on the sheet surface is accurately measured. I can not

  The present specification provides a technique for solving the above-mentioned problems. The present specification provides a technique capable of accurately measuring the load acting on the sheet surface that deforms in response to the load.

  The present specification shows a load measuring device that measures a load acting on a sheet surface that deforms according to a load. The load measuring device includes a sensor device and an arithmetic device connected to the sensor device. The sensor device includes an inertial sensor disposed on the seat surface and a force sensor disposed on the seat surface. The arithmetic device obtains detection values from the inertial sensor and the force sensor, calculates the attitude angle of the force sensor based on the detection value of the inertia sensor, and uses the calculated attitude angle to detect the detection value of the force sensor to correct.

  According to the above configuration, even if the seat surface is deformed according to the load and the main axis direction of the force sensor is changed according to the deformation of the seat surface, the arithmetic device is based on the detection value of the inertia sensor Since the attitude angle of the force sensor is calculated and the detected value of the force sensor is corrected using the calculated attitude angle, the load acting on the seat surface can be accurately measured.

  In the load measuring device described above, the computing device may estimate the deformation state of the seat surface based on the detection value of the inertial sensor, and calculate the attitude angle of the force sensor based on the estimated deformation state of the seat surface You may

  According to the above configuration, even when the inertial sensor and the force sensor are disposed at different places on the seat surface, the attitude angle of the force sensor can be calculated based on the detection value of the inertial sensor. .

  In the above-described load measuring device, the computing device may set only a part of the inertial sensor and the force sensor as a detection target, and acquire the detection value from the inertial sensor and the force sensor to be detected.

  When the number of inertial sensors and force sensors disposed on the seat surface increases, it takes a long time for the arithmetic device to acquire detection values from the respective inertial sensors and force sensors. According to the above configuration, the arithmetic device sets only a part of the inertial sensor and the force sensor as a detection target, and acquires detection values from the inertial sensor and the force sensor to be detected. The time required to obtain detection values from the inertial sensor and the force sensor can be shortened.

  In the load measuring device described above, the computing device identifies an inertial sensor in which the deviation obtained by subtracting the detected value as the reference from the detection value of the inertial sensor in the previous detection or the time change rate of the deviation exceeds a predetermined threshold. Alternatively, the inertial sensor and the force sensor disposed in the vicinity of the identified inertial sensor may be set as detection targets in the subsequent detection.

  According to the above configuration, for example, since the inertial sensor and the force sensor disposed in the vicinity of the portion where the detected value of the inertial sensor such as the acceleration and angular velocity largely fluctuates are set as the detection target, It is possible to measure at a high speed the appearance of the load at the point where there was a large variation in the way of action.

It is a figure showing typically composition of load measuring device 2 of an example. It is a top view which shows the state before the sensor apparatus 6 of an Example is attached to the sheet | seat surface 4a. It is sectional drawing which shows the state before the sensor apparatus 6 of an Example is attached to the sheet | seat surface 4a. The sensor apparatus 6 of the Example is attached to the sheet | seat surface 4a, and it is sectional drawing which shows the state which a load does not act on the sheet | seat surface 4a. The sensor apparatus 6 of the Example is attached to the sheet | seat surface 4a, and it is sectional drawing which shows the state which a load is acting on the sheet | seat surface 4a. It is a flowchart which shows the example of the process which the calculating | arithmetic apparatus 8 of an Example performs. It is a flowchart which shows another example of the process which the calculating | arithmetic apparatus 8 of an Example performs. It is a top view which shows the state before the sensor apparatus 6 of a modification is attached to the sheet | seat surface 4a. It is a flowchart which shows the example of the process which the calculating | arithmetic apparatus 8 of a modification performs. It is a flowchart which shows another example of the process which the arithmetic unit 8 of a modification performs.

(Example)
FIG. 1 schematically shows the configuration of a load measuring device 2 of the present embodiment. The load measuring device 2 measures, for example, a load acting on the seat surface 4 a of the seat 4 on which a passenger sits on a vehicle such as a car. The load measuring device 2 includes a sensor device 6 provided on the surface of the seat surface 4 a and an arithmetic device 8 connected to the sensor device 6. In the following description, a coordinate system fixed to a vehicle on which the seat 4 is mounted is referred to as a reference coordinate system (X, Y, Z).

  As shown in FIGS. 2-5, the sensor device 6 includes a flexible support film 6a, a plurality of inertial sensors 10 and a plurality of force sensors 12 disposed on the support film 6a. It should be noted that in FIG. 1, the illustration of the plurality of inertial sensors 10 and the plurality of force sensors 12 is omitted for clarity of illustration. As shown in FIG. 2, in the load measuring device 2 of the present embodiment, the plurality of inertial sensors 10 and the plurality of force sensors 12 are arranged in a grid shape on the support film 6a. In the load measuring device 2 of the present embodiment, the number of the plurality of inertial sensors 10 is smaller than the number of the plurality of force sensors 12. Although not shown, each inertial sensor 10 is provided with a 3-axis acceleration sensor and a 3-axis angular velocity sensor. Therefore, each inertial sensor 10 can detect three-axis acceleration and three-axis angular velocity. Further, each force sensor 12 can detect loads of three axes. Each inertial sensor 10 and each force sensor 12 are connected to the arithmetic unit 8.

As shown in FIG. 3, in the state before the sensor device 6 is attached to the sheet surface 4 a, the principal axis directions (x ₁ , y ₁ , z ₁ ) of the respective inertial sensors 10,. , Y, Z). Further, the principal axis directions (x ₂ , y ₂ , z ₂ ),... Of the force sensor 12 coincide with the reference coordinate system (X, Y, Z).

As shown in FIG. 4, when the sensor device 6 is attached to the seat surface 4 a, the support film 6 a deforms according to the shape of the seat surface 4 a. Thereby, the main axis directions (x ₁ , y ₁ , z ₁ ),... Of the inertial sensor 10 change. Further, the main axis directions (x ₂ , y ₂ , z ₂ ),... Of the force sensor 12 change.

As shown in FIG. 5, in the state where the sensor device 6 is attached to the seat surface 4a, when a rider acts on the seat surface 4a and a load is applied, the seat surface 4a is deformed, and the support film 6a is also on the seat surface 4a. It deforms following the deformation. Thereby, the main axis directions (x ₁ , y ₁ , z ₁ ),... Of the inertial sensor 10 are further changed. Further, the main axis directions (x ₂ , y ₂ , z ₂ ),... Of the force sensor 12 further change. In the inertial sensor 10, one disposed at a position where the load does not deform even when the load acts on the seat surface 4a, that is, the reference coordinate system (X, Y, Z) even when the load acts on the seat surface 4a In the following, one that does not change the relationship of the attitude with the above is also referred to as a reference inertial sensor 10a.

  The arithmetic device 8 shown in FIG. 1 outputs the distribution of the load acting on the seat surface 4 a based on the detection values of the inertia sensor 10 and the force sensor 12 of the sensor device 6. Hereinafter, the process performed by the arithmetic device 8 according to the present embodiment will be described with reference to FIG.

  In step S2, the arithmetic unit 8 instructs all inertial sensors 10 and force sensors 12 to output detection values, and the acceleration detection values of three axes and the angular velocity detection values of three axes of each inertial sensor 10, and The load detection values of the three axes of each force sensor 12 are acquired.

  In step S4, the arithmetic unit 8 estimates the deformation state (profile) of the sheet surface 4a. Specifically, the arithmetic device 8 is, for example, a location where each inertial sensor 10 is arranged based on temporal change of the triaxial acceleration detection value and the triaxial angular velocity detection value of each inertial sensor 10, for example. The deformation state of the sheet surface 4a is identified. Then, the arithmetic unit 8 estimates the entire deformation state of the sheet surface 4 a by performing fitting using a spline function.

  In step S6, the arithmetic unit 8 calculates the attitude angles of the respective force sensors 12. Specifically, based on the deformation state of the entire sheet surface 4a estimated in step S4, for example, the arithmetic device 8 specifies the deformation state of the sheet surface 4a at the location where each force sensor 12 is disposed. Do. Then, the arithmetic device 8 calculates the attitude angle of each force sensor 12 from the deformation state of the seat surface 4 a at the position where each force sensor 12 is disposed.

In step S8, the arithmetic device 8 corrects the detection value of each force sensor 12 based on the attitude angle of each force sensor 12. For example, the arithmetic device 8 uses the transformation matrix A that reflects the attitude angle of the force sensor 12 from the detection values (F _x , F _y , F _z ) of the force sensor 12 to obtain the reference coordinate system (X, Y). , Z), and the detection values (F _x ′, F _y ′, F _z ′) of the force sensor 12 are calculated.

  Here, regarding the attitude angle of the force sensor 12, the rotation angle around the X axis is the roll angle ψ, the rotation angle around the Y axis is the pitch angle θ, and the rotation angle around the Z axis is the yaw angle φ. Is given by the following equation.

In step S10, the arithmetic unit 8 outputs the load distribution on the sheet surface 4a based on the detection values (F _x ', F _y ', F _z ') of the respective force sensors 12 corrected in step S8. . After step S10, the process returns to step S2.

  According to the process shown in FIG. 6, it is possible to correct the detection value of the force sensor 12 by reflecting the deformation state of the seat surface 4 a estimated from the detection value of the inertia sensor 10. By this, it is possible to accurately measure the load distribution acting on the sheet surface 4a.

  Arithmetic unit 8 may perform the process shown in FIG. 7 instead of the process shown in FIG. The process shown in FIG. 7 will be described below.

  In step S12, the arithmetic unit 8 sets all the inertial sensors 10 and the force sensors 12 as detection targets.

  In step S14, the arithmetic unit 8 instructs the inertial sensor 10 and the force sensor 12 to be detected to output detection values, and the acceleration detection values of the three axes of the inertia sensor 10 and the angular velocity detection values of the three axes are detected. And the load detection value of 3 axes of each force sensor 12 is acquired.

  In step S16, the arithmetic unit 8 estimates the deformation state (profile) of the sheet surface 4a in the vicinity of each force sensor 12 to be detected. Specifically, the arithmetic device 8 changes, for example, temporal changes in acceleration detection values of three axes of the respective inertial sensors 10 disposed in the vicinity of the respective force sensors 12 of detection targets and angular velocity detection values of the three axes. Based on the above, the deformation state of the seat surface 4a at the place where each inertial sensor 10 is arranged is specified. Then, the arithmetic device 8 performs fitting using a spline function to estimate the deformation state of the sheet surface 4 a in the vicinity of each of the force sensors 12 to be detected.

  In step S18, the arithmetic device 8 calculates the attitude angles of the force sensors 12 to be detected. Specifically, based on the deformation state of the sheet surface 4a estimated in step S16, for example, the arithmetic device 8 specifies the deformation state of the sheet surface 4a at the location where each force sensor 12 is disposed. Then, the arithmetic device 8 calculates the attitude angle of each force sensor 12 from the deformation state of the seat surface 4 a at the position where each force sensor 12 is disposed.

In step S20, the arithmetic device 8 corrects the detection value of each force sensor 12 based on the attitude angle of each force sensor 12 to be detected. For example, in the same manner as the processing shown in FIG. 6, the arithmetic unit 8 converts the transformation matrix A reflecting the attitude angle of the force sensor 12 from the detection values (F _x , F _y , F _z ) of the force sensor 12. The detected values (F _x ', F _y ', F _z ') of the force sensor 12 after conversion to the reference coordinate system (X, Y, Z) are calculated.

In step S22, the arithmetic unit 8 outputs the load distribution on the sheet surface 4a based on the detection values (F _x ', F _y ', F _z ') of the respective force sensors 12 corrected in step S20. . As for the force sensor 12 not to be detected in step S14, the previous detection values (F _x ', F _y ', F _z ') may be used as they are.

  In step S24, the arithmetic unit 8 updates the inertial sensor 10 and the force sensor 12 to be detected. After step S24, the process returns to step S14.

  In step S24, the inertial sensor 10 and the force sensor 12 to be detected next can be set from various viewpoints. For example, the computing device 8 may specify the inertial sensor 10 and the force sensor 12 to be detected next based on the detected value of the acceleration in the Z direction in the inertial sensor 10. In this case, the arithmetic device 8 first subtracts the detected value of the Z-direction acceleration of the inertial sensor 10a as a reference from the detected values of the Z-direction acceleration of the inertial sensor 10 for all the inertial sensors 10 The inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10 calculated and having the calculated deviation exceeding a predetermined threshold value are set as an inertial sensor 10 and a force sensor 12 to be detected next. It is also good. Alternatively, the arithmetic device 8 calculates, for all the inertial sensors 10, deviations obtained by subtracting the detected values of the Z-direction acceleration of the inertial sensor 10a as a reference from the detected values of the accelerations of the inertial sensor 10 in the Z direction. The inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10 whose temporal change rate of the calculated deviation exceeds a predetermined threshold value are set as the inertial sensor 10 and the force sensor 12 to be detected next. May be In this case, the inertial sensor 10 and the force sensor 12 in the vicinity of the portion where the acceleration in the Z direction has largely changed can be the next detection target. In the above process, an acceleration in the X direction or Y direction may be used instead of the acceleration in the Z direction.

  Alternatively, the arithmetic unit 8 sets the inertial sensor 10 and the force sensor 12 to be detected next based on the displacement amount in the Z direction in the inertial sensor 10 calculated from the acceleration in the Z direction in the inertial sensor 10. It is also good. In this case, the arithmetic device 8 first calculates a deviation obtained by subtracting the displacement amount in the Z direction of the inertial sensor 10a as a reference from the displacement amount in the Z direction calculated for the inertial sensors 10 for all the inertial sensors 10 Even if the inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10 whose calculated deviation exceeds a predetermined threshold value are set as the inertial sensor 10 and the force sensor 12 to be detected next. Good. Alternatively, the arithmetic unit 8 calculates a deviation obtained by subtracting the displacement amount in the Z direction of the inertial sensor 10a serving as a reference from the detection value of the displacement amount in the Z direction calculated for the inertial sensor 10 for all inertial sensors 10 Then, the inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10 in which the time change rate of the calculated deviation exceeds a predetermined threshold value are used as the inertial sensor 10 and the force sensor 12 next to be detected. It may be set. In this case, the inertial sensor 10 and the force sensor 12 in the vicinity of the portion where the displacement amount in the Z direction has largely changed can be the next detection target. In the above process, instead of the displacement amount in the Z direction, the displacement amount in the X direction or the Y direction may be used.

  Alternatively, the arithmetic device 8 may set the inertial sensor 10 and the force sensor 12 to be detected next based on the detection value of the angular velocity around the X axis in the inertial sensor 10. In this case, the arithmetic device 8 first subtracts the detected values of the angular velocity around the X axis of the inertial sensor 10a serving as a reference from the detected values of the angular velocity around the X axis of all the inertial sensors 10 Deviation is calculated and inertia sensor 10 and force sensor 12 in the vicinity of inertia sensor 10 whose calculated deviation exceeds a predetermined threshold value are set as inertia sensor 10 and force sensor 12 to be detected next You may Alternatively, the arithmetic unit 8 calculates a deviation obtained by subtracting the detected value of the angular velocity around the X axis of the inertial sensor 10a serving as a reference from the detected values of the angular velocity around the X axis of all the inertial sensors 10 Then, the inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10 in which the time change rate of the calculated deviation exceeds a predetermined threshold value are used as the inertial sensor 10 and the force sensor 12 next to be detected. It may be set. In this case, the inertial sensor 10 and the force sensor 12 in the vicinity of the portion where the angular velocity around the X axis has largely changed can be the next detection target. In the above process, instead of the angular velocity around the X-axis, the angular velocity around the Y-axis or the Z-axis may be used.

  Alternatively, based on the rotation angle (roll angle) around the X axis in the inertial sensor 10 calculated from the angular velocity around the X axis in the inertial sensor 10, the arithmetic device 8 and the force sense to be detected next are The sensor 12 may be set. In this case, first of all, with respect to all the inertial sensors 10, the arithmetic unit 8 calculates the rotational angle around the X axis of the inertial sensor 10a as a reference from the rotational angles (roll angles) around the X axis calculated for the inertial sensors 10. Next, the inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10 whose calculated deviation exceeds a predetermined threshold value is calculated by calculating a deviation obtained by subtracting (roll angle). And may be set as the force sensor 12. Alternatively, the arithmetic unit 8 subtracts the rotation angle (roll angle) of the inertial sensor 10a serving as a reference from the rotation angle (roll angle) of the inertia sensor 10 about the X axis for all the inertial sensors 10 Of the inertial sensor 10 and the force sensor 12 in the vicinity of the inertial sensor 10, which is next to be detected, and the force The sensor 12 may be set. In this case, the inertial sensor 10 and the force sensor 12 in the vicinity of the portion where the rotation angle (roll angle) around the X axis has largely changed can be the next detection target. In the above process, instead of the rotation angle (roll angle) around the X axis, a rotation angle (pitch angle) around the Y axis or a rotation angle (yaw angle) around the Z axis may be used.

  According to the process shown in FIG. 7, it is possible to reduce the time required for the arithmetic device 8 to acquire the detection value as compared to the case where all the inertial sensors 10 and the force sensors 12 are to be detected. The load distribution of the seat surface 4a can be output at high speed.

  Although the above embodiment has described the case where the inertial sensor 10 and the force sensor 12 are not arranged at the same place in the sensor device 6, for example, as shown in FIG. 8, the inertial sensor 10 and the force sensor 12 , May be co-located and rigidly coupled to one another. In this case, the attitude angle of the force sensor 12 can be obtained directly from the detection value of the inertia sensor 10. In this case, the computing device 8 can measure the load distribution of the seat surface 4 a by performing the process shown in FIG. 9.

  In step S32, the arithmetic unit 8 instructs all inertial sensors 10 and force sensors 12 to output detection values, and the acceleration detection values of three axes and the angular velocity detection values of three axes of each inertial sensor 10, and The load detection values of the three axes of each force sensor 12 are acquired.

  In step S34, the arithmetic unit 8 calculates the attitude angles of the respective force sensors 12. Specifically, the arithmetic device 8 is based on the temporal change of the acceleration detection values of the three axes of the inertial sensor 10 provided corresponding to the respective force sensors 12 and the angular velocity detection values of the three axes. The attitude angle of each force sensor 12 is calculated.

In step S36, the arithmetic unit 8 corrects the detection value of each force sensor 12 based on the attitude angle of each force sensor 12. For example, in the same manner as the processing shown in FIG. 6 and FIG. 7, the arithmetic device 8 is a conversion matrix that reflects the attitude angle of the force sensor 12 from the detection values (F _x , F _y , F _z ) of the force sensor 12. Using A, the detection values (F _x ′, F _y ′, F _z ′) of the force sensor 12 after conversion to the reference coordinate system (X, Y, Z) are calculated.

In step S38, the arithmetic unit 8 outputs the load distribution on the sheet surface 4a using the detection values (F _x ', F _y ', F _z ') of the respective force sensors 12 corrected in step S36. . After step S38, the process returns to step S32.

  According to the process shown in FIG. 9, it is possible to correct the detection value of the force sensor 12 by reflecting the attitude angle of the force sensor 12 calculated from the detection value of the inertia sensor 10. By this, it is possible to accurately measure the load distribution acting on the sheet surface 4a.

  Arithmetic unit 8 may perform the process shown in FIG. 10 instead of the process shown in FIG. The process shown in FIG. 10 will be described below.

  In step S42, the arithmetic unit 8 sets all the inertial sensors 10 and the force sensors 12 as detection targets.

  In step S44, the arithmetic device 8 instructs the inertial sensor 10 and the force sensor 12 to be detected to output detection values, and the acceleration detection values of the three axes of the inertia sensor 10 and the angular velocity detection values of the three axes are detected. And the load detection value of 3 axes of each force sensor 12 is acquired.

  In step S46, the arithmetic unit 8 calculates the attitude angles of the force sensors 12 to be detected. Specifically, the arithmetic device 8 is based on the temporal change of the acceleration detection values of the three axes of the inertial sensor 10 provided corresponding to the respective force sensors 12 and the angular velocity detection values of the three axes. The attitude angle of each force sensor 12 is calculated.

In step S48, the arithmetic device 8 corrects the detection value of each force sensor 12 based on the attitude angle of each force sensor 12 to be detected. For example, the computing device 8, 6, 7, in the same manner as the processing shown in FIG. 9, the detection value of the force sensor _{12 (F x, F y,} F z) from the attitude angle of the force sensor 12 Using the reflected conversion matrix A, the detection values (F _x ′, F _y ′, F _z ′) of the force sensor 12 after conversion to the reference coordinate system (X, Y, Z) are calculated.

In step S50, the arithmetic unit 8 outputs the load distribution on the sheet surface 4a using the detection values (F _x ', F _y ', F _z ') of the respective force sensors 12 corrected in step S48. . As for the force sensor 12 not to be detected in step S44, the previous detection values (F _x ', F _y ', F _z ') may be used as they are.

  In step S52, the arithmetic unit 8 updates the inertial sensor 10 and the force sensor 12 to be detected in the same manner as the process shown in FIG. After step S52, the process returns to step S44.

  According to the process shown in FIG. 10, it is possible to reduce the time required for the arithmetic device 8 to acquire the detection value as compared to the case where all the inertial sensors 10 and the force sensors 12 are to be detected. The load distribution of the seat surface 4a can be output at high speed.

  As described above, the load measuring device 2 according to the embodiment measures the load acting on the sheet surface 4 a that is deformed according to the load. The load measuring device 2 includes a sensor device 6 and an arithmetic device 8 connected to the sensor device 6. The sensor device 6 includes an inertial sensor 10 disposed on the seat surface 4 a and a force sensor 12 disposed on the seat surface 4 a. Arithmetic unit 8 acquires detection values from inertia sensor 10 and force sensor 12, calculates the attitude angle of force sensor 12 based on the detection value of inertia sensor 10, and uses the calculated attitude angle to calculate force sense. The detected value of the sensor 12 is corrected.

  In the load measuring device 2 according to one embodiment, the computing device 8 estimates the deformation state of the seat surface 4a based on the detection value of the inertia sensor 10, and the force sensor based on the estimated deformation state of the seat surface 4a. Calculate 12 attitude angles.

  In the load measuring device 2 according to one embodiment, the computing device 8 sets only a part of the inertial sensor 10 and the force sensor 12 as a detection target, and the detected value from the inertial sensor 10 and the force sensor 12 to be detected To get

  In the load measuring device 2 according to one embodiment, a deviation obtained by subtracting the detection value as a reference from the detection value of the inertial sensor 10 in the previous detection by the arithmetic device 8 or a time change rate of the deviation has a predetermined threshold value. The excess inertial sensor 10 is identified, and the inertial sensor 10 and the force sensor 12 disposed in the vicinity of the identified inertial sensor 10 are set as detection targets in the subsequent detection.

  As mentioned above, although the specific example of this invention was described in detail, these are only an illustration and do not limit a claim. The art set forth in the claims includes various variations and modifications of the specific examples illustrated above. The technical elements described in the present specification or the drawings exhibit technical usefulness singly or in various combinations, and are not limited to the combinations described in the claims at the time of application. In addition, the techniques exemplified in the present specification or the drawings can simultaneously achieve a plurality of purposes, and achieving one of the purposes itself has technical utility.

2: load measuring device, 4: seat, 4a: seat surface, 6: sensor device, 6a: support film, 8: arithmetic device, 10: inertia sensor, 10a: reference inertia sensor, 12: force sensor

Claims (4)

A load measuring device for measuring a load acting on a sheet surface that deforms according to a load,
A sensor device,
It has an arithmetic unit connected to the sensor unit,
The sensor device
An inertial sensor placed on the seat surface,
It has a force sensor placed on the seat surface,
The computing device
Obtain detection values from inertial sensors and force sensors,
Calculate the attitude angle of the force sensor based on the detection value of the inertia sensor,
A load measuring device that corrects a detected value of a force sensor using a calculated attitude angle. The computing device
The deformation state of the seat surface is estimated based on the detected value of the inertial sensor,
The load measuring device according to claim 1, wherein an attitude angle of the force sensor is calculated based on the estimated deformation state of the seat surface. The computing device
Set only part of the inertial sensor and force sensor as the detection target,
The load measuring device according to claim 1 or 2, wherein detected values are acquired from an inertial sensor to be detected and a force sensor. The computing device
A deviation obtained by subtracting a reference detection value from a detection value of the inertia sensor in the previous detection or an inertial sensor whose time rate of change of the deviation exceeds a predetermined threshold value;
The load measuring device according to claim 3, wherein an inertial sensor and a force sensor disposed in the vicinity of the identified inertial sensor are set as detection targets in the subsequent detection.

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